A known alignment conveyor apparatus includes an input conveyor which supplies a product, a variable-speed conveyor which performs a position correction of the product, and an output conveyor which carries the product transferred from the variable-speed conveyor (for instance, see Patent Document 1).
Here, a speed of the output conveyor is constant at a normal time, and a reference speed of the variable-speed conveyor is set to be the same as that of the output conveyor. Additionally, the speed of the variable-speed conveyor is set to the reference speed except when the position correction is performed.
Meanwhile, the speed of the input conveyor is set to be slower than that of the variable-speed conveyor. The reason is because when products which are in close contact with each other are supplied from the input conveyor, the speed of the variable-speed conveyor is made faster than that of the input conveyor so that the products which are in close contact with each other are made to be separated from each other in terms of the speed difference between the conveyors (for instance, see Patent Document 1).
In addition, the position correction of the product loaded on the variable-speed conveyor is performed by a technique in which a position correction amount is calculated on the basis of a distance from a current position to a transfer position of the output conveyor and a target position of the output conveyor, and the correction amount is corrected by the respective variable-speed conveyors in a sharing manner.
The position correction is performed in the forward direction, that is, the position correction is performed only in the direction in which the speed of the variable-speed conveyor becomes fast.
Additionally, the position correction amount is determined by calculating the position correction amount in consideration of the maximum speed of the variable-speed conveyor.
Patent Document 1: JP-A-2003-292146 (pages 10 to 17, FIG. 1)